The specific aim of this proposal is to continue the mission of the UC Davis/NIH NeuroMab Facility: to develop a comprehensive library of monoclonal antibodies (mAbs) optimized for use in the brain (i.e. NeuroMabs). This renewal remains driven by the need, articulated in the original proposal to create the UC Davis/NIH NeuroMab Facility, and that still remains, to greatly expand the availability of such brain-optimized mAbs for use in basic, translational and clinical neuroscience research. There remains a need for high- quality antibodies against defined gene products that serve as the crucial bridge between the inventory of genes expressed in the brain, and understanding how their products determine brain function in normal and pathological conditions. However, many necessary reagents remain either unavailable, or when available suffer from a lack of efficacy and specificity, especially when used in mammalian brain preparations. The availability of high-quality, reliable mAbs that have been optimized for use in mammalian brain (i.e. NeuroMabs) is of utmost importance to virtually all areas of neuroscience. We will continue to pursue the generation of a comprehensive library of NeuroMabs by using recombinant and/or synthetic immunogens corresponding to fragments of neuronal proteins in an intense immunization protocol that yields large numbers of IgG-secreting hybridomas from a relatively short immunization period. These large hybridoma pools will be screened for those mAbs that recognize the cognate antigen in heterologous cells, and then the entire positive pool subjected to comprehensive biochemical and immunohistochemical analyses of their efficacy and specificity in brain. The resultant brain-optimized NeuroMabs will continue to be made available at very low cost to the research community as tissue culture supernatants or as purifed IgG preparations. Investigators will continue to use these NeuroMabs for determining the presence and relative abundance of the cognate antigens in developing, adult, aged, and diseased brain, their cellular and subcellular localization, functionally relevant post-translational modifications, and protein-protein interactions. Moreover, NeuroMabs will continue to find additional applications in direct functional analyses of proteins, in diagnostic procedures, and as therapeutics.